How severe is CVE-2021-22556?

CVE-2021-22556 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2021-22556 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22556?

CVE-2021-22556 affects Google Fuchsia. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-22556?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-22556 published?

CVE-2021-22556 was published on 2022-05-03 and last updated on 2026-06-17.

CVE-2021-22556

CVE-2021-22556 is a medium-severity vulnerability in Google Fuchsia with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.6
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Google Fuchsia
Published: 2022-05-03
Last modified: 2026-06-17

Description

The Security Team discovered an integer overflow bug that allows an attacker with code execution to issue memory cache invalidation operations on pages that they don’t own, allowing them to control kernel memory from userspace. We recommend upgrading to kernel version 4.1 or beyond.

Frequently asked questions

What is CVE-2021-22556?: The Security Team discovered an integer overflow bug that allows an attacker with code execution to issue memory cache invalidation operations on pages that they don’t own, allowing them to control kernel memory from userspace. We recommend upgrading to kernel version 4.1 or beyond.
How severe is CVE-2021-22556?: CVE-2021-22556 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2021-22556 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22556?: CVE-2021-22556 affects Google Fuchsia. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-22556?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-22556 published?: CVE-2021-22556 was published on 2022-05-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:google:fuchsia:*:*:*:*:*:*:*:*

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Other CWE-190 (Integer Overflow or Wraparound) vulnerabilities

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CVE-2015-5097 — Critical (CVSS 10.0): Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC…
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